Regenerating-Type Mask : A self-contained breathing apparatus that removes CO2 from the exhaled air of the wearer and enriches it with additional oxygen supplied from a cylinder
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}